IMAGE PROCESSING METHOD, IMAGE PROCESSING DEVICE, IMAGE PROCESSING PROGRAM, AND STORAGE MEDIUM STORING IT

PROBLEM TO BE SOLVED: To provide an image processing method, an image processing device, an image processing program, and a storage medium storing the image processing program capable of detecting an angle of a line shown by image data with high precision. SOLUTION: In a step S1, edge intensity of a target pixel is calculated. In a step S2, the edge intensity is compared with a threshold value. In a step S3, an edge direction is calculated. In a step S4, an edge direction histogram is created. In a step S6, a peak angle is decided based on the created edge direction histogram. In a step S8, a polar coordinate histogram is created by Hough transformation based on edge pixels within an area around the peak angle. In a step S10, a temporary line is decided based on the polar coordinate histogram. In a step S11, a longest line segment of the temporary line is detected. In a step S12, an angle of the straight line is decided from regression line based on a least square method. COPYRIGHT: (C)2006,JPO&NCIPI